This invention concerns both a method and an installation for the submersed, automatically controlled production of fermentation vinegar from ethanol.
Production proceeds in two stages, there being one or more of the preliminary stage.
An arrangement for the production of fermentation acetic acid is known from Swiss Pat. No. 375,315, which operates in principle with two refining units of similar capacity. After complete evacuation of one of the vessels, accordingly as all of the alcohol is consumed, it will be inoculated with a portion from the second vessel and refilled with fresh mash. The end point of the acidifying is determined as a function of the subsidence of the temperature of the medium.
Another two-stage method, according to DE-PS No. 26 57 330, supplies an acid concentration above 15% acetic acid, with an alcohol content of less than 0.5%. There, the bacteria multiplication and acidifying are to be conducted in a first fermentation phase. In a second fermentation phase the acidifying along with the introduction of the acetic acid bacteria is practically finished. Acetic acid bacteria do not multiply much and hence produce acetic acid very slowly. This influences the economy of the method.
Further disadvantages of the known processes are that with a controlling of the vinegar ejection with regard to the temperature a process variable is used which can be influenced by outside considerations and not simply according to the microbiological process. An additional disadvantage of the methods mentioned is that the utilization of the alcohol in the finishing fermentation step is incomplete.